This invention relates to steerable motorized wheelchairs for the handicapped, and in particular to a novel and extremely useful means for removably coupling front wheel portions and rear wheel portions to obtain assembled wheelchairs having various different functions.
It is known to provide wheelchairs of the type generally having three wheels in a tricycle configuration, with the front wheel being steerable. It is further known to provide kits having different functions which, once assembled together, produce wheelchairs having a certain desired mix of functions, as described in co-pending U.S. application Ser. No. 917,404, assigned to the assignee of the present application, and the disclosure of which is incorporated herein by reference. For instance, one front unit may have a single wheel, and handlebars for steering that wheel. Another front unit may have two wheels, controlled by a steering wheel. To add yet other permutations, both the one- and two-wheel front units may be motorized or un-motorized. Similarly rear units, which would generally have two wheels, may carry a seat and/or a battery pack and/or be motorized. Further, the wheels may be of varying sizes, such as relatively larger for relatively rough terrain, or smaller for smoother surfaces and indoors. Clearly a dealer's inventory requirements are reduced if he can combine the various front units and rear units as needed rather than attempting to stock all the various assembled combintions.
Fortress Scientific, of Buffalo, N.Y., makes a three-wheel sheelchair with front and rear units that come apart to facilitate storage and transportation of the chairs, referring to it as the model 2000FS. This apparatus is not adapted, however, to connect interchangeable front and rear units.
Other apparatuses are also known which include front and rear wheel units which are detachable from each other. For instance, U.S. Pat. Nos. 3,605,929, 3,658,354, 3,945,449 and British Pat. No. 608,184 all show such devices. In all of the disclosed devices, however, no provision is made to prevent free play in the connection, resulting in disagreeable ride characteristics.
This invention relates to improvements over the devices described above and to solutions to the problems raised thereby.